经颅多普勒超声诊断大脑中动脉狭窄的价值

The value of diagnosis of middie cerebral artery stenosis with transcranial Doppler ultrasound

目的探讨经颅多普勒超声（transcranial Doppler ultrasound，TCD）诊断大脑中动脉（middlecerebralartery，MCA）狭窄的价值。方法对行数字减影血管造影（digitalsubtractangiography，DSA）和TCD检查的缺血性脑血管病患者的临床资料进行回顾性分析，以DSA为金标准，分析TCD诊断MCA狭窄的敏感性和特异性。对正常以及不同狭窄程度MCA的TCD血流速度进行比较，计算MCA不同狭窄程度时TCD血流速度的最佳截断值。结果103例患者DSA证实存在MCA狭窄或闭塞，其中轻度狭窄12例，中度狭窄22例，重度狭窄40例，闭塞39例。与DSA相比，TCD检测中度以上MCA狭窄或闭塞的敏感性为78．8％，特异性为96％，准确度为93％，漏诊率为21．2％，误诊率为4％。轻度狭窄组与正常组之间血流速度无显著差异，中度狭窄组与正常组之间血流速度存在显著差异（P〈0．001），中度狭窄组与重度狭窄组之问血流速度无显著差异。判定中度狭窄的最佳收缩期峰值血流速度截断值为163．5cm／s，平均血流速度的最佳截断值为108．5cm／s。结论TCD在诊断MCA狭窄或闭塞方面具有一定的优势，可作为DSA检查之前的一种安全而廉价的筛选手段。

Objective To explore the value of the diagnosis of middle cerebral artery （MCA） stenosis with transcranial Doppler ultrasound （TCD）. Methods The clinical data in patients with ischemic cerebrovascular disease examined with digital subtract angiography （DSA） and TCD were analyzed retrospectively. DSA was used as a gold standard to analyze the sensitivity and specificity of the diagnosis of MCA stenosis with TCD. The normal and TCD blood flow velocity with different deffees of stenosis were compared. The best cut-off point of the TCD blood flow velocity of MCA at different degree of stenosis was calculated. Results DSA confirmed that 103 patients had MCA stenosis or occlusion, in which 12 were mild stenosis, 22 were moderate stenosis, 40 were severe stenosis, and 39 were occlusion. Compared to DSA, the sensitivity of TCD in detection of moderate and severe MCA stenosis or occlusion was 78. 8%, the specificity was 96. 0%, and the accuracy was 93.0%, the missed diagnosis rate was 21.2%, and the misdiagnosis rate was 4. 0%. As to the blood flow velocity, there was no sifftificant difference between the mild stenosis and normal groups; while there was significant difference between the moderate stenosis and normal groups （/9 〈 0. 001）. In addition, there was no significant difference in blood flow velocity between the moderate stenosis and severe stenosis groups. Determining the cut-off value of the best peak systolic velocity of the moderate stenosis was 163.5 cm/s, while the best cut-off value of the mean velocity was 108.5 cm/s. Conclusions TCD has certain advantages in the diagnosis of the MCA stenosis or occlusion, and it can be used as a safe and inexpensive screening means before DSA examination.